Flow restoration systems and methods for use

ABSTRACT

Apparatus and methods are provided for removing obstructive material within a body lumen. The apparatus includes a macerator device deployable from a sheath that includes an expandable cage carried by a shaft and within a constraint tube. The shaft is movable relative to the constraint tube for deploying and expanding the cage within a body lumen such that an open end of the cage is oriented towards obstructive material. The cage is advanced to capture the material or the material is directed into the cage using an expandable member expanded beyond the material and retracted to direct the material into the cage. The cage is withdrawn into the constraint tube to compress the cage radially inwardly. Materials extending through apertures in the cage are sheared off by a sharpened edge of the constraint tube. The smaller, sheared off particles are then aspirated from the body lumen through the sheath.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/655,688, filed Oct. 19, 2012, and published as U.S. Patent App. Pub.No. 2013/0289589 on Oct. 13, 2013, which is a divisional of U.S. patentapplication Ser. No. 12/564,892, filed Sep. 22, 2009, and issued as U.S.Pat. No. 8,298,252 on Oct. 30, 2012, which claims the benefit of U.S.Provisional Patent App. No. 61/099,171, filed Sep. 22, 2008, U.S.Provisional Patent App. No. 61/143,603, filed Jan. 9, 2009, and U.S.Provisional Patent App. No. 61/152,227, filed Feb. 12, 2009, which areall incorporated by reference herein, as if fully set forth in theirentirety.

FIELD OF THE INVENTION

The present invention relates generally to apparatus for treatingobstructive material, e.g., thrombus, stenosis, and/or unwanted materialwithin a body lumen of a patient, e.g., within a tubular graft,aorta-venous fistula, blood vessel, and the like. More particularly, thepresent invention relates to apparatus for removing or otherwisecapturing thrombus or other obstructive material within a body lumen,and to methods for making and using such apparatus.

BACKGROUND

Flow within a blood vessel or other body lumen within a patient'svasculature may become constricted or ultimately interrupted for avariety of reasons. For example, a vessel may gradually narrow due toinflammation and/or cell proliferation. In addition, thrombus may formdue to such narrowing or other flow problems within a vessel.

Flow within a blood vessel or other body lumen within a patient'svasculature may become constricted or ultimately interrupted for avariety of reasons. For example, a vessel may gradually narrow due toinflammation and/or cell proliferation. In addition, thrombus may formdue to such narrowing or other flow problems within a vessel.

Another approach to removing the adherent material is to advance arotating structure that can abrade the surface of the adherent materialor become entangled in the adherent material, thereby forcing theadherent material to release from the vessel wall. For example, theArrow Treratola device has several helical wires that expand radiallyoutward to contact the vessel wall. These wires are spun at a high speedvia a driveshaft connected to an electric motor in the hand piece of thedevice. During operation, the Treratola device rubs against the insidewall of the vessel as it is advanced. Upon engaging adherent material,the device abrades the inside surface of that material, and in manycases, the device may break through the interface between the adherentmaterial and the vessel wall. In this event, the adherent material canbe peeled off the vessel wall and become wrapped around the helicalwires of the Treratola device.

While this may address the immediate goal of removing the adherentmaterial from the vessel wall, it is often difficult to remove thematerial from the vessel itself since the Treratola device does notoffer any method to unwind or aspirate the material. As the Treratoladevice is removed from the vessel, it typically passes through aclosefitting orifice such as an introducer sheath. Any material that iswound around the Treratola device is typically pushed off as it entersthe sheath, and such material thus remains in the vessel.

Accordingly, apparatus and methods for removing material fromaorta-venous grafts, blood vessels, or other body lumens would beuseful.

SUMMARY

The present invention is directed to apparatus for treating a body lumenof a patient, e.g., a tubular graft, aortavenous fistula, blood vessel,and the like. More particularly, the present invention is directed toapparatus for removing or otherwise capturing thrombus or otherobstructive material within a body lumen, and to methods for making andusing such apparatus.

In accordance with one embodiment, a system is provided for removingobstructive material from a body lumen. The system includes an outertubular member comprising a proximal end, a distal end, and a lumenextending between the proximal and distal ends. Optionally, an annularexpandable occlusion member may be provided on the outer tubular memberdistal end. The system also includes a macerator device insertablethrough the lumen and comprising an elongate shaft, an expandable cagecoupled to a distal end of the elongate shaft, and a constraint tubehaving a distal opening with a sharpened edge, wherein the shaft and thecage are axially moveable relative to the constraint tube. Optionally,the constraint tube may be fixedly coupled to an inner surface of theouter tubular member or the constraint tube may be movable independentlyof the outer tubular member.

The cage may include a plurality of apertures, and the distal sharpenededge of the constraint tube may be configured for shearing off materialthat protrudes through the apertures as the cage is proximally withdrawninto the constraint tube. Optionally, the inner surface of the cage mayinclude a plurality of inwardly protruding barbs. The cage may includedistal protruding structures and/or, thick struts and thin strutsconnecting the thick struts together. Optionally, one or more controlwires may be coupled to the distal protruding structures of the cage,wherein the control wire(s) may be configured for drawing the protrudingstructures together into a closed configuration when the cage is in anexpanded configuration. Optionally, a driveshaft may be operably coupledto the cage for causing the cage to rotate during advancement throughthe body lumen or the system may include an actuator for manuallyrotating the cage. In exemplary embodiments, the distal protrudingstructures may have a smooth edge, a slotted edge, or a serpentine edge.

In an exemplary embodiment, the system may further include an elongatetreatment member comprising an expandable treatment element selectivelyexpandable for directing the obstructive material within the body lumeninto the cage when the cage is in an expanded configuration. Theelongate treatment member may be insertable through a lumen in themacerator device shaft. Alternatively, the elongate treatment member maybe insertable through the outer tubular member lumen adjacent to themacerator device shaft. Optionally, in this alternative, the cage mayhave an uninterrupted path or other opening through which the elongatetreatment member may pass.

In accordance with another embodiment, a method is provided for removingobstructive material from a body lumen that includes introducing anouter tubular member into the body lumen, the outer tubular memberincluding a lumen and a distal opening. A macerator device may beintroduced through the outer tubular member lumen into the body lumen.In an exemplary embodiment, the macerator device may include an elongateshaft, an expandable cage coupled to a distal end of the elongate shaft,and a constraint tube having a distal opening. The expandable cage maybe deployed out of the constraint tube distal opening by distallyadvancing the elongate shaft relative to the constraint tube, andexpanded within the body lumen. Obstructive material may be capturedwithin the cage, and then the cage may be proximally withdrawn into theconstraint tube. Material that protrudes through apertures in the cageas the cage collapses may be sheared off, e.g., by a sharpened edge ofthe constraint tube distal opening, In addition or alternatively,sheared off material may be aspirated into the outer tubular memberdistal opening. Optionally, the method may also include expanding anocclusion element on the outer tubular member distal end, e.g., toprevent obstructive material from passing proximally beyond the distalend of the outer tubular member.

In an exemplary embodiment, the method may further include introducingan elongate treatment member including a distal expandable treatmentelement through the outer tubular member lumen and into the body lumensuch that the expandable treatment element, in a collapsedconfiguration, is positioned distal to the obstructive material and thecage is positioned proximal to the obstructive material.

The expandable treatment element may be expanded and proximallywithdrawn towards the expanded cage such that obstructive material iswithdrawn into the cage by the expandable treatment element.

In another exemplary embodiment, the method may also include advancingthe expanded cage towards the obstructive material and rotating the cageduring advancement until the obstructive material becomes entangled in adistal portion of the cage. Rotation of the cage may cause obstructivematerial to be separated from the vessel wall, and the cage may bewithdrawn into the constraint tube. The withdrawal may release theobstructive material from the cage distal portion and/or withdraw theobstructive material into the constraint tube. Optionally, the cage maybe redeployed, expanded, and/or withdrawn, one or more additional times,e.g., to separate and/or withdraw obstructive material into the cage.

In accordance with another embodiment, an apparatus is provided forremoving obstructive material from a body lumen that includes an outertubular member including a proximal end, a distal end sized forintroduction into a body lumen, and a lumen extending between theproximal and distal ends; an elongate shaft including proximal anddistal ends and movable axially within the tubular member lumen; and anexpandable macerator cage including a first end attached to the distalend of the shaft and a second free end.

The cage is expandable from a collapsed configuration when the cage isdisposed within the tubular member lumen and an expanded configurationwhen the cage is deployed from the tubular member lumen.

In one embodiment, the cage includes a tubular structure including awall extending between the first and second ends, the second enddefining an opening communicating with an interior of the cage in theexpanded configuration for capturing obstructive material within theinterior of the cage. The wall may include a plurality of struts and/orapertures such that, when the cage is withdrawn back into the tubularmember lumen after capturing obstructive material therein, the distalend of the tubular member slidably engages the wall of the cage orotherwise separates obstructive material captured by the cage thatextends through the apertures and the cage is compressed back towardsthe collapsed configuration.

In accordance with still another embodiment, a system is provided forremoving obstructive material from a body lumen that includes an outertubular member including a proximal end, a distal end sized forintroduction into a body lumen, and a lumen extending between theproximal and distal ends; an obstruction device deployable from thetubular member to a location beyond obstructive material intended to beremoved, the obstruction device including an expandable member on adistal end thereof; and a macerator device. The macerator device mayinclude an expandable cage carried on a distal end of a shaft and aconstraint tube for maintaining the cage in a collapsed configuration,e.g., to allow the macerator device to be introduced into the body lumenthrough the tubular member lumen. The cage may be deployable from adistal end of the constraint tube and expandable to an expandedconfiguration within a body lumen. In one embodiment, the cage mayinclude an open end communicating with an interior of the cage in theexpanded configuration for capturing obstructive material within theinterior of the cage.

BRIEF DESCRIPTION OF THE DRAWINGS

It will be appreciated that the exemplary apparatus shown in thedrawings are not necessarily drawn to scale, with emphasis instead beingplaced on illustrating the various aspects and features of theillustrated embodiments.

FIG. 1 is a side view of an exemplary embodiment of a flow restorationsystem including an occlusion device and a macerator device deployablefrom an access sheath.

FIG. 2A is a cross-sectional side view of an access sheath that may beincluded in the system of FIG. 1, including an expandable member on adistal end of the access sheath.

FIG. 2B is a cross-sectional side view of an alternative embodiment ofan access sheath that may be included in the system of FIG. 1, includingan expandable member on a distal end of the access sheath.

FIG. 3 is a detail of an inner surface of a cage of a macerator devicethat may be included in the system of FIG. 1.

FIGS. 4A and 4B are cross-sectional side views of exemplary embodimentsof a constraint tube that may be included in a macerator device in thesystem of FIG. 1.

FIG. 5 is a cross-sectional side view of an alternative embodiment of anaccess including an integral constraint tube that may be included in thesystem of FIG. 1.

FIG. 6 is a side view of another exemplary embodiment of a flowrestoration system including an occlusion device and a macerator devicedeployable from an access sheath.

FIGS. 7-10 are cross-sectional views of a body lumen within a patient'sbody, showing a method for removing obstructive material within the bodylumen.

FIGS. 11A and 11B are perspective views of another exemplary embodimentof a macerator device cage in expanded and collapsed configurations,respectively.

FIG. 12A is a top view of a flat pattern that may be incorporated intothe macerator device cage of FIGS. 11A and 11B.

FIG. 12B is a detail of a portion of the flat pattern of FIG. 12A.

FIG. 13 is a perspective detail of the macerator device cage shown inFIGS. 11A and 11B being rotated in a direction A.

FIGS. 14A and 14B are cross-sectional views of another exemplaryembodiment of a macerator device cage that includes control wires fordirecting a distal end of the cage between an open configuration and aclosed configuration, respectively.

FIG. 14C is a cross-sectional view of an alternative embodiment of themacerator device cage of FIGS. 14A and 14B that includes control wiresand a sleeve around the control wires for directing the cage between anopen configuration and a closed configuration.

FIGS. 15A-15C are side views of alternative embodiments of distal tipsthat may be provided on a macerator device cage, such as the cage shownin FIGS. 11A and 11B.

FIGS. 16A-16H are cross-sectional views of a body lumen within apatient's body, showing another method for removing obstructive materialwithin the body lumen.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Turning to the drawings, FIG. 1 shows an exemplary embodiment of anapparatus 10 for treating a body lumen, e.g., for removing thrombus,clots, objects, debris, and/or other unwanted or obstructive materialfrom within the body lumen, such as a blood vessel, aorta-venousfistula, tubular graft, and the like. Generally, the apparatus 10includes an outer access sheath or other tubular member 20, and,optionally, an obstruction device 30 and a macerator device 40, whichtogether may provide a flow restoration system, e.g., for removingobstructive material from within body lumens in a patient's body. Inaddition, such a system may include one or more additional componentsnot depicted, e.g., one or more guidewires, syringes or other sources ofinflation media and/or vacuum, and the like, within the body lumen.

The sheath 20 may be an elongate tubular body, e.g., an introducer orprocedure sheath, including a proximal end (not shown), a distal end 22sized for introduction into a body lumen, and a lumen 24 extendingbetween the proximal end and the distal end 22. The sheath 20 may beconfigured for percutaneous placement within a body lumen, e.g.,including a rounded or otherwise substantially atraumatic tip tofacilitate advancement into and/or along body lumens within a patient'sbody.

The sheath 20 may have a substantially uniform construction along itslength, or alternatively, the construction may be varied. For example, aproximal portion of the sheath 20 may be substantially rigid orsemi-rigid to facilitate advancement of the apparatus 10 by pushing orotherwise manipulating the proximal end. In addition or alternatively, adistal portion of the sheath 20 may be flexible, e.g., to facilitatebending and/or advancement through tortuous anatomy without substantialrisk of kinking or buckling. In exemplary embodiments, the sheath 20 maybe formed from materials such a metal, plastic, e.g., PEEK, GrilamedL25, and the like, or composite materials. The sheath 20 may have alength between about five and one hundred thirty centimeters (5-130 em)and an outer diameter between about 1.6 to 2.0 millimeters, and thelumen 24 may have a diameter between about 1.4 and 1.8 millimeters.

Optionally, the sheath 20 may include a handle or hub on the proximalend (not shown). The handle may be shaped to facilitate holding ormanipulating the apparatus 10 or individual components of the apparatus10, as described further below. In addition, the handle may include aport communicating with the lumen 24, e.g., for infusing fluid into thelumen 24 and/or aspirating material from the lumen 24, e.g., around themacerator device 40 and/or obstruction device 30. For example, asyringe, vacuum line, and the like may be coupled to the port foraspirating obstructive material received within the lumen 24 of thesheath 20 and/or disposed adjacent the distal end 22 within a bodylumen, as described further below.

Optionally, the sheath 20 may include an expandable member or otherocclusion element carried on the distal end 22, e.g., to stabilize thesheath 20 within a body lumen and/or to seal the body lumen from fluidflow past the distal end 22 during a procedure. For example, FIG. 2Ashows a sheath 20′ including an expandable member 26′ on its distal end22′ within a body lumen 50. The expandable member 26′ may be a compliantballoon, e.g., formed from compliant material that may expandelastically proportional to the amount of inflation media delivered intothe balloon 26,′ a semi-compliant balloon, or a non-compliant balloon,e.g., a PTA balloon, if desired. In this embodiment, the sheath 20′ mayinclude an inflation lumen (not shown) extending from the proximal endof the sheath 20′ to the distal end 22′ and communicating with aninterior of the balloon 26.′ A source of inflation media and/or vacuum,e.g., a syringe with saline or other fluid (not shown), may be coupledto the proximal end of the sheath 20′ for delivering inflation mediainto the balloon 26′ via the inflation lumen and/or aspirating fluidfrom the balloon 26,′ e.g., to facilitate collapsing the balloon 26′after a procedure. Alternatively, the expandable member 26′ may bemechanically or otherwise expandable, e.g., including an expandableframe or other structure within or otherwise coupled to a membrane (notshown).

The expandable member 26′ may be expandable from a low profile,collapsed configuration, e.g., disposed against the outer surface of thesheath 20′ to facilitate introduction of the sheath 20,′ and a highprofile, expanded configuration, e.g., to engage or otherwise contact aninner surface of a body lumen 50 within which the sheath 20′ isintroduced. In the expanded configuration, the expandable member 26′ mayprovide a substantially fluid tight seal within the body lumen 50, e.g.,to prevent substantial physiologic flow along the body lumen 50, whichmay otherwise allow particles of loose material to move past the sheath20 into other parts of the patient's body where they may cause harm.

In addition or alternatively, the expandable member 26′ may alsosubstantially secure and/or stabilize the sheath within the body lumen50, e.g., to prevent inadvertent movement of the sheath 20′ within thebody lumen 50 during treatment.

During use, the expandable member 26′ may be maintained in the lowprofile configuration when the sheath 20′ is introduced, and thenexpanded to the high profile configuration once the sheath 20′ ispositioned within the body lumen 50 being treated. The expandable member26′ may remain expanded as obstructive material is removed from the bodylumen 50 via the sheath 20′ or other component of the apparatus 10, asdescribed further below. Once the body lumen 50 is sufficiently treated,the expandable member 26′ may be collapsed to restore physiologic flowwithin the body lumen 50.

In an alternative embodiment shown in FIG. 2B, an access sheath 20″ maybe provided that includes an expandable member 26″ that extends beyondthe distal end 22″ of the sheath 20″ to provide an expandable distal tipfor the sheath 20.″ Thus, the expandable member 26″ may provide aconical or other transition extending from an enlarged distal tiptowards the lumen 24″ of the sheath 20,″ e.g., such that maceration ofobstructive material may be performed within or adjacent the distal tipof the expandable member 26″ if desired. During maceration, particles ofobstructive material may be liberated within or adjacent the lumen 24″of the sheath 20,″ thereby facilitating aspiration of the particles fromthe body lumen 50 into the lumen 24.″ Additional information on theaccess sheath 20″ and/or expandable member 26″ may be found inPCT/US09/53237, filed Aug. 8, 2009, the entire disclosure of which isexpressly incorporated by reference herein.

Referring back to FIG. 1, the obstruction device 30 generally includes ashaft or other elongate member 32 including a proximal end (not shown),a distal end 33 sized for introduction through the sheath 20, e.g., viathe lumen 24, and carrying an expandable obstruction or treatment member34 on the distal end 33. Generally, the obstruction member 34 isexpandable from a collapsed configuration (not shown), e.g., sized forintroduction through the lumen 24 of the sheath 20, and an expandedconfiguration (shown in FIG. 1) for engaging or otherwise contacting awall of a body lumen within which the obstruction member 34 is expanded.In an exemplary embodiment, the obstruction member 34 may be a balloon,e.g., a compliant, semi-compliant, or non-compliant balloon, expandableto a substantially spherical or cylindrical shape. In this embodiment,the shaft 32 may include an inflation lumen (not shown) in communicationwith an interior of the obstruction member 34, e.g., for selectivelyexpanding and collapsing the obstruction member 34. Optionally, theobstruction member 34 may include a core wire and/or helical structure(not shown), e.g., such that the obstruction member may adopt a helicalshape in the expanded configuration.

Exemplary devices that may be used for the obstructive device 30 aredisclosed in co-pending application Ser. No. 12/497,135, filed Jul. 2,2009, the entire disclosure of which is expressly incorporated byreference herein. Alternatively, the obstruction member 34 may include aframe or other mechanically expandable structure (not shown), ifdesired.

With continued reference to FIG. 1, the macerator device 40 generallyincludes a shaft or other elongate member 42 including a proximal end(not shown), a distal end 43 also sized to fit within the lumen 24 ofthe sheath 20, and an expandable cage 44 carried on the distal end 43.Optionally, the shaft 42 may include a lumen or other track (not shown)for slidably receiving the obstruction device 30 therethrough, asdescribed further below. In addition or alternatively, the shaft 42 mayinclude one or more additional lumens (not shown), e.g., for receiving aguidewire or other rail (also not shown), one or more actuator wires orcables (also not shown), and the like, as described further below.

As shown, the cage 44 is an open or porous expandable structureincluding a closed proximal or first end 44 a coupled to the shaft 42and an open distal or second end 44 b, e.g., to accommodate receivingobstructive material within the cage 44, as described further below.Generally, the cage 44 includes a plurality of struts 44 a extendingbetween the first and second ends 44 a, 44 b and/or around a peripheryof the cage 44, thereby defining a cylindrical or other tubular outerwall including a plurality of apertures 46, e.g., at least adjacent thefirst end 44 a. The struts 44 a and/or apertures 46 may be sized toaccommodate expansion and/or collapse of the cage 44 and/or to define adesired pore size that prevents particles larger than the desired poresize from escaping once captured within the cage 44, as describedfurther below.

The cage 44 is expandable from a low-profile, collapsed configuration(not shown), e.g., to accommodate introduction through the sheath 20,and a high-profile, expanded configuration (shown in FIG. 1) where thecage 44 expands radially outwardly, e.g., to contact the wall of a bodylumen within which the cage 44 is deployed and/or expanded.

Optionally, as shown in FIG. 3, the cage 44 may include a plurality ofbarbs or other features 41 projecting radially inwardly from the struts44 a, e.g., to engage and/or provide additional traction withobstructive material captured within the cage 44, as discussed furtherbelow.

The cage 44 may be formed from a variety of materials, e.g., capable ofelastically or plastically moving between the collapsed and expandedconfigurations one or more times. For example, the cage 44 may be formedfrom elastic or superelastic materials, e.g., metals, such as stainlesssteel, Nitinol, and the like, plastics, or composite materials. In anexemplary embodiment, the cage 44 may be formed from a tube withportions of the tube removed to define the struts 44 a and/or apertures46, e.g., by laser cutting, etching, mechanical cutting, and the like.Alternatively, the cage 44 may be formed from a sheet also with portionsremoved to define the struts 44 a and/or apertures 46, e.g., by lasercutting, etching, mechanical cutting, stamping, and the like, which maybe rolled into a tubular shape with edges of the sheet attachedtogether, e.g., by welding, soldering, bonding with adhesive, fusing,and the like.

The cage 44 may then be attached to the shaft 42, e.g., by substantiallypermanently attaching the closed end 44 a around the distal end 43 ofthe shaft 42, e.g., by crimping, bonding with adhesive, fusing, wrappinga collar, wire or other material around the closed end 44 a, and thelike. Thus, the closed end 43 may be fixed in the collapsedconfiguration, while the rest of the cage 44 may be free to expand fromthe collapsed configuration to the expanded configuration. In anexemplary embodiment, the cage 44 may be formed from superelasticmaterial that may be heat treated to program the expanded configurationinto the cage 44, while allowing the cage 44 to be resilientlycompressed and maintained in the collapsed configuration.

Thus, in the embodiment shown in FIG. 1, the cage 44 may be aself-expanding structure, e.g., resiliently compressible radiallyinwardly to the collapsed configuration yet biased to expand towards theexpanded configuration. Alternatively, the cage 44 may be mechanicallyexpanded and collapsed, e.g., using an actuator (not shown) on theproximal end of the macerator device 40 coupled to the cage 44.

To maintain a self-expanding cage 44 in the collapsed configuration,e.g., during introduction through or before deployment from the sheath20, the macerator device

40 may include a constraint tube 48 slidably disposed around the shaft42. The constraint tube 48 may be an elongate tubular body including aproximal end (not shown), a distal end 48 a, and a lumen 49 extendingtherebetween that is sized to receive the shaft 42 and cage 44 with thecage 44 in the collapsed configuration. Alternatively, other removableconstraints may be provided around the cage 44 to maintain the cage 44in the collapsed configuration until it is desired to deploy and expandthe cage 44 within a body lumen, e.g., one or more removable wires woundaround the cage 44, a tearaway sleeve, and the like (not shown).

The distal end 48 a of the constraint tube 48 may be sized to beslidably disposed within the sheath 20, e.g., to accommodateintroduction of the macerator device 40 through the lumen 24 of thesheath 20. The constraint tube 48 and the shaft 42 and cage 44 may bemovable axially relative to one another, e.g., to allow the cage 44 tobe retracted within the constraint tube 48 and/or deployed from theconstraint tube 48. Thus, the constraint tube 48 may maintain the cage44 in the collapsed configuration, e.g., during introduction into a bodylumen through the sheath 20, and allow the cage 44 to be deployed fromthe constraint tube 48 such that the cage 44 assumes the expandedconfiguration.

The proximal ends (not shown) of the shaft 42 and/or constraint tube 48may extend or otherwise be coupled to the proximal end of the sheath 20and may be actuatable from the proximal end of the sheath 20. Forexample, the sheath 20 may include a handle or hub (not shown) on itsproximal end, which may include one or more actuators for advancing themacerator device 40 from the distal end 22 of the sheath 20 and/or fordeploying the cage 44 from and covering the cage 44 with the constrainttube 48. The shaft 42 and/or constraint tube 48 may extend into thehandle, or one or more cables, wires, rods, or other actuator elements(not shown) may be coupled between the shaft 42 and/or constraint tube48 and one or more actuators on the handle.

For example, a first actuator, e.g., a slider, button, dial, and thelike, may be provided on the handle (not shown) to advance and/orretract the entire macerator device 40 relative to the sheath 20, e.g.,to deploy the cage 44 from the distal end 22 of the sheath 20 whilestill covered by the constraint tube 48. A second actuator, e.g.,another slider, button, dial, and the like (also not shown), may then beactivated to expose the cage 44, e.g., by advancing the shaft 42 andcage 44 relative to the constraint tube 48 or retracting the constrainttube 48 without substantial movement of the cage 44. Exemplary handlesand/or actuators that may be provided on the apparatus 10 are disclosedin application Ser. No. 12/497,135 incorporated by reference above.

Alternatively, the sheath 20 and macerator device 40 may be structurallyseparate devices, and the macerator device 40 may be introduced into thesheath 20, e.g., via a port or other opening in the proximal end of thesheath 20. For example, a handle or hub (not shown) may be provided onthe proximal end of the sheath 20 that includes a port (also not shown)communicating with the lumen 24 that may accommodate introduction of themacerator device 40 and/or other devices therein. Optionally, the portmay include one or more seals, e.g., a hemostatic seal that mayaccommodate receiving the macerator device 40 therein while providing asubstantially fluid-tight seal to prevent bodily fluids from escapingfrom the lumen 24. In this alternative, the macerator device 40 itselfmay include a handle or hub (not shown) on its proximal end thatincludes one or more actuators (also not shown) for manipulating theshaft 42 and cage relative to the constraint tube 48, similar to theactuators described above.

Optionally, in a similar manner, the obstruction device 30 may becoupled to the sheath 20 and/or macerator device 40, e.g., with one ormore actuators (not shown) on a handle of the apparatus 10 for deployingand/or withdrawing the obstruction device 30. Alternatively, theobstruction device 30 may be a separate device from the sheath 20 and/ormacerator device 40, and the macerator device 40 may include a port forreceiving the obstruction device 20, e.g., similar to the port describedabove.

Optionally, as shown in FIGS. 4A and 4B, the constraint tube 48 may beconfigured to facilitate removing excess material captured by the cage44. For example, the distal end 48 a of the constraint tube 48 mayinclude one or more features that slide or otherwise interact with thecage struts 44 a, e.g., to trim excess material that extends out of thecage apertures 46 when the cage 44 is withdrawn back into the constrainttube 48 after capturing obstructive material within the cage 44. Thus,as the cage 44 enters the constraint tube 48 and is compressed towardsthe collapsed configuration, the features on the distal end 48 a of theconstraint tube 48 may shear or otherwise trim excess material thatprotrudes out of the cage apertures 46.

In an exemplary embodiment, shown in FIG. 4A, the distal end 48 a of theconstraint tube 48 may include a sharpened edge 47 extending around adistal opening 43 communicating with the lumen 49 that is suitable forcutting off excess obstructive material that may protrude through theapertures 46 of the cage 44. In the embodiment shown in FIG. 4A, thesharpened edge 47 may be a single-ground edge, e.g., that may shearalong the outer surface of the cage 44 during withdrawal to cut orotherwise separate obstructive material extending through the apertures46. Alternatively, as shown in FIG. 4B, a constraint tube 48′ may beprovided that includes a double-ground sharpened edge 47′ extendingaround distal opening 43.′ The double-ground sharpened edge 47′ may cutexcess obstructive material similarly to the single-ground edge 47, butmay be more resistant to damage as the cage 44 passes into the lumen 49′of the constraint tube 48.′ For example, since the cutting edge 47′ hasa slightly larger diameter than the lumen 49′ of the constraint tube 48′itself, the cutting edge 47′ may not contact the outer surface of thecage 44 during withdrawal of the cage 44 but remain spaced slightlyapart from the cage 44.

In an alternative embodiment, shown in FIG. 5, the constraint tube 48shown in FIGS. 4A and 4B may be omitted, and a sheath 60 may be used toconstrain the cage 44 (not shown) in the collapsed configuration duringintroduction and/or to remove excess material during withdrawal of thecage 44. Similar to the previous embodiments, the sheath 60 includes aproximal end (not shown), a distal end 62, and a lumen 64 extendingtherebetween. Unlike the previous embodiments, the sheath 60 includes aconstraint tube 48″ incorporated into the distal end 64, e.g., withinthe lumen 64.

The constraint tube 48″ may be a relatively short tubular body extendinga short distance into the lumen 64 and including an exposed andsharpened edge 47″ around a distal opening 43,″ e.g., a single-ground ordouble-ground edge, similar to the previous embodiments. The constrainttube 48″ may be substantially permanently attached within the lumen 64or otherwise to the distal end 62, e.g., by bonding with adhesive,interference fit, fusing, sonic welding, and the like, thereby providinga transition from the distal opening 43″ into the lumen 64.

During use, the cage 44 may be advanced from the lumen 64 and out of thedistal opening 43″ whereupon the cage 44 may freely expand towards theexpanded configuration.

After unwanted material is captured within the cage 44 (as describedfurther elsewhere herein), the cage 44 may be withdrawn back into thesheath 60 through the distal opening 43,″ whereupon excess obstructivematerial extending through the apertures 46 of the cage 44 may be cut orotherwise separated by the sharpened edge 47″ as the cage 44 collapses.

In a further alternative, the sheath 20 shown in FIG. 1, may be used toconstrain the cage 44 during introduction and/or withdrawal and theconstraint tube 48 may be omitted entirely. Unlike previous embodiments,however, when the cage 44 is withdrawn into the sheath 20, the cage 44may not be collapsed to as small a size due to the relatively largerdiameter of the sheath 20 compared to a constraint tube 48 introducedthrough the sheath 20. In this alternative, a portion of the obstructivematerial may remain within the cage 44 after withdrawal into the sheath20. In other words, the macerator device cage 44 may be used to captureand remove the obstructive material without trimming off excessiveobstructive material. Alternatively, the sheath 20 itself may include asharpened distal edge (not shown) or a sharpened tip may be attached tothe distal end 22 of the sheath 20 (also not shown), e.g., to cut offexcess obstructive material during withdrawal of the cage 44, whileobstructive material within the cage 44 is withdrawn into the sheath 20within the cage 44.

With further reference to FIG. 1, in the embodiment shown, the shaft 42of the macerator device 40 includes a lumen that slidably receives theshaft 32 of the obstruction device 30, e.g., such that the maceratordevice 40 and the obstruction device 30 have a concentric, telescopingarrangement relative to one another. Alternatively, as shown in FIG. 6,an apparatus 10′ may be provided in which a macerator device 40 and anobstruction device 30 are provided in a side-by-side arrangementrelative to an outer sheath 20. In this alternative, the sheath 20,obstruction device 30, and macerator device 40 may be constructedsimilar to the embodiments described above. Optionally, the maceratordevice 40 may include a cage 44 that includes an uninterrupted path 45defined by struts 44 a of the cage 44 that extends axially along atleast a portion of the cage 44 to accommodate the obstruction device 30passing through the cage 44 while allowing the cage 44 to closesubstantially completely to the collapsed configuration.

In this embodiment, the obstruction device 30 and macerator device 40may be received in a common lumen 24 of the sheath 20, as shown in FIG.6. Alternatively, the sheath 20 may include separate lumens (not shown)disposed adjacent one another, each for receiving one of the obstructiondevice 30 and the macerator device 40. Otherwise structure and operationof the apparatus 10′ may be similar to that described with reference toapparatus 10 of FIG. 1.

Turning to FIGS. 7-10, an exemplary method is shown for removingmaterial, e.g., thrombus or other obstructive material 52, within a bodylumen 50. The body lumen 50 may be a blood vessel, aorta-venous fistula,tubular graft, xenograft, and the like, e.g., within a patient's armthat communicates between an adjacent vein and artery. Alternatively,the apparatus and methods described herein may be used to treat otherlocations within a patient's body, e.g., within the patient'svasculature or other body lumens. Although apparatus 10 shown in FIG. 1is shown and described in association with FIGS. 7-10, it will beappreciated that the methods described herein may be performed using anyof the apparatus and systems described herein.

Generally, the method may involve trapping thrombus or other obstructivematerial between an expanded obstruction member 34 and an expanded cage44, e.g., such that the material may be captured by the cage 44, brokeninto smaller particles, removed within the cage 44, and/or aspiratedfrom the body lumen 50 through sheath 20. Initially, as shown in FIG. 7,the sheath 20 may be introduced into a body lumen 50, e.g.,percutaneously from an entry site using conventional methods, andmanipulated to position the distal end 22 of the sheath 20 within thebody lumen 50 adjacent to and spaced apart from obstructive material 52.Optionally, if the sheath 20 includes an expandable member, e.g.,balloon 26, 26′ as shown in FIG. 2A or 2B, on the distal end 22, theexpandable member (not shown) may be expanded any time after the distalend 22 is placed at a desired position within the body lumen 50, e.g.,to prevent subsequent movement of the sheath 20 and/or to substantiallyseal the body lumen 50 from fluid flow proximally past the sheath 20.

In addition or alternatively, aspiration may be applied to the lumen 24of the sheath 20, e.g., at any time after introducing the distal end 22of the sheath 20 into the body lumen 50. For example, a syringe orvacuum line may be coupled to the proximal end of the sheath 20 andactivated to apply a substantially continuous vacuum to the lumen 24 todraw loose material within the body lumen 50 into the lumen 24.

The obstruction device 30 may then be introduced into the body lumen 50from the sheath 20 and advanced past the material 52 with theobstruction member 34 in the lowprofile configuration (not shown). Forexample, the obstruction device 30 may be loaded into the lumen 24 ofthe sheath 20 and advanced through the length of the sheath 20 into thebody lumen 50, or the obstruction device 30 may be integral with orpreloaded into the sheath 20 before the procedure and merely deployedfrom the sheath 20. Optionally, a distal tip of the obstruction device30 may be sufficiently small and/or sharp to pass freely through thematerial 52 and/or may be rounded or otherwise substantially atraumaticto pass along the wall of the body lumen 50 past the material 52. Oncethe obstruction member 34 is positioned distally beyond the material 52,the obstruction member 34 is expanded to the high-profile condition, asshown in FIG. 7.

Next, with reference to FIG. 8, the macerator device 40 may be deployedfrom the sheath 20, e.g., over or adjacent the shaft 32 of theobstruction device 30. The macerator device 40 may be advanced until thecage 44 (maintained in the collapsed configuration within the constrainttube 48) is disposed proximal or adjacent to the material 52 oppositethe expanded obstruction member 34. Thus, the obstructive material 52may be bounded by the obstruction member 34 on one side and themacerator device 40 on the other. Once positioned within the body lumen50, the cage 44 may be expanded within the body lumen 50, e.g., bydeploying the cage from the constraint tube 48, whereupon the cage 44may resiliently expand radially outwardly to contact the wall of thebody lumen, as shown in FIG. 8.

Turning to FIG. 9, the obstruction device 30 may then be retractedproximally towards the cage 44 to pull material 52 within the body lumen50 towards and into the macerator device cage 44, as shown.Alternatively, the cage 44 may be advanced towards the obstructiondevice 30 to capture material 52 within the cage 44, with theobstruction member 34 preventing distal migration of the material 52away from the cage 44. As described above, if the cage 44 includes barbs41, e.g., as shown in FIG. 3, the barbs 41 may partially penetrate orotherwise engage with the material 52 captured within the cage 44, e.g.,to prevent migration of the material 52 relative to the cage 44.

Optionally, the obstruction device 30 and/or macerator device 40 mayinclude a locking mechanism, e.g., one or more cooperating detents,tabs, or other features (not shown), that may substantially secure theobstruction device 30 relative to the cage 44 when the obstructiondevice 30 has been placed a predetermined distance from the cage 44,e.g., substantially adjacent the cage 44 such that the obstructiondevice 30 substantially encloses the material 52 within the cage 44, asshown in FIG. 9. Alternatively, a locking mechanism may be provided on aproximal end of the apparatus 10, e.g., on a handle (not shown), whichmay be locked and unlocked to selectively secure the obstruction device30 relative to the cage 44. With the locking mechanism engaged, theobstruction device 30 may not be directed distally away from the cage44, e.g., such that subsequent movement of the obstruction device 30 iscoupled to movement of the cage 44.

Turning to FIG. 10, the macerator device cage 44 and expandedobstruction member 34 may then be directed proximally towards the sheath20, e.g., until the cage 44 enters the constraint tube 48. If a vacuumhas not been applied previously, a source of vacuum may be activated toaspirate material released within the body lumen 50 into the lumen 24 ofthe sheath 24, as shown. As the cage 44 is drawn into the constrainttube 48, the cage 44 may be compressed radially inwardly, therebyforcing portions of the material 52 through the apertures 46 in the cage44. The portions of the material 52 exposed through the apertures 46 maybe sheared off, e.g., by the sharpened distal edge 47, 47′ (not shown,see FIGS. 4A and 4B) of the constraint tube 48, reducing the material 52into many smaller particles 53 within the body lumen 50. The looseparticles 53 may be removed from the body lumen 50, e.g., by aspiration,through the sheath lumen 24, as shown.

Notably, the reduced particle size may be a function of the size of theapertures 46 in the cage 44. Thus, the size of the cage apertures 46 maybe chosen to reduce the particle size of the material 52 to a desiredmaximum cross-section, e.g., such that the reduced diameter particles 53may be reliably removed though the sheath 20 without substantial risk ofoccluding the sheath lumen 24.

In one embodiment, the cage 44 may be compressed to a collapsedconfiguration as the cage 44 is withdrawn into the constraint tube 48 inwhich the interior space of the cage 44 is minimized, thereby squeezingsubstantially all of the captured material 52 through the apertures 46of the cage 44.

The extruded and/or sheared particles 53 may then be aspirated into thelumen 24 of the sheath 20. Alternatively, the cage 44 may havesufficient interior space in the collapsed configuration such that atleast some captured material may remain within the cage 44 when the cage44 is withdrawn fully into the constraint tube 48.

With the cage 44 withdrawn fully into the constraint tube 48, themacerator device 40 and obstruction device 30 may be withdrawn into thesheath 20 and the apparatus 10 removed from the patient's body.Alternatively, the obstruction member 34 may be collapsed and theobstruction device 30 advanced through another section of obstructivematerial (not shown) within the body lumen 50. In this alternative, themacerator device 40 may then be redeployed to capture and remove thematerial, e.g., by repeating the steps described above. Optionally, theentire apparatus 10 may be introduced into another body lumen (notshown), and the obstruction device 30 and macerator device 40 redeployedto capture and/or remove obstructive material in other regions of thepatient's body, if desired.

Once sufficient material has been removed, the obstruction member 34 ofthe obstruction device 30 may be collapsed and the obstruction device 30may be withdrawn into the macerator device 40 or into the sheath 20 ifthe macerator device 40 has already been withdrawn into the sheath 20.The aspiration within the sheath 20 may be discontinued, the expandablemember on the sheath 20 may be collapsed (if provided on the sheath 20),and the sheath 20 may be withdrawn from the body lumen 50.

Turning to FIGS. 11A-13, another embodiment of a macerator cage 144 isshown that may be included in any of the apparatus and/or systemsdescribed herein. Generally, the macerator cage 144 includes a closedproximal or first end 144 a and an open distal or second end 144 b,similar to the previous cage 44. The cage 144 may include a plurality ofstruts 116, 118 extending between the first and second ends 144 a, 144 band/or around a periphery of the cage 144, thereby defining acylindrical or other tubular outer wall including a plurality ofapertures 146, similar to the previous cage 44.

The closed end 144 a of the cage 144 may include a collar portion 141,which may be attached to a macerator device shaft 42 (not shown, see,e.g., FIG. 1), while the open distal end 143 of the cage 144 may includea plurality of distally protruding elements or distal tips 112. Forexample, FIG. 11A shows the cage 144 in an expanded configuration inwhich the collar portion 141 remains compressed, e.g., due to itsattachment to a shaft (not shown), and the cage 144 defines asubstantially continuous diameter extending from the closed end 144 a tothe open end 144 b. FIG. 11B shows the cage 144 in a compressedconfiguration, e.g., in which the cage 144 may be constrained orotherwise compressed around the shaft and/or within a constraint tube(also not shown).

Unlike the cage 44 of FIG. 1, as can be best seen in FIGS. 12A and 12B,the cage 144 includes at least two different types of struts 116, 118.For example, the cage 144 may include a plurality of relatively thickstruts 116 that extend substantially continuously along a length of thecage 144, e.g., in a first helical configuration between the first andsecond ends 144 a, 144 b. In addition, the cage 144 may include aplurality of relatively thin struts 118, which may connect adjacentthick struts 116 together. As shown, the thin struts 118 are notsubstantially continuous as are the thick struts 116, but may extend ina discontinuous pattern helically and/or circumferentially around thecage 44. Optionally, the thin struts 118 may also have bends or otherfeatures, e.g., relatively thinned or perforated portions, that allowthe struts 118 to bend relatively easily compared to the thick struts116.

The apertures 146 may be defined by the spaces between the thick struts116 and the thin struts 118, thereby defining a desired pore size forthe cage 144. The cage 144 may be formed using similar materials andmethods as those previously described above.

The distal tips 112 on the open end 144 b of the cage 144 may provide asubstantially atraumatic distal end for the cage 144, e.g., to preventpuncture or other damage to a wall of a body lumen within which the cage144 is deployed. In addition or alternatively, the distal tips 112 maybe sufficiently flexible to allow the distal tips 112 to twist helicallyand/or interlock with one another during use. FIGS. 15A-15C showalternative configurations of a distal tip that may be provided on thecage 144, e.g., to facilitate engaging and/or removing obstructivematerial within a body lumen. For example, FIG. 15A shows an exemplaryembodiment of a distal tip 112 a that includes a substantially straightconfiguration with a smooth leading edge 125.

Alternatively, FIG. 15B shows another exemplary embodiment of a distaltip 112 b that includes a series of slots or indentations 126 spacedapart along a length of the distal tip 112 b, e.g., that may allow thedistal tips 112 b to entangle with each other and/or with theobstructive material captured or otherwise engaged by the distal tips112 b to facilitate removal, as described further below with referenceto FIGS. 16A-16H. For example, when the cage 144 is rotated, the distaltips 112 b and obstructive material may be wound together, e.g., suchthat portions of other distal tips 112 b and/or obstructive material mayenter the slots 126 and the distal tips 112 b become interlocked withone another. FIG. 15C shows yet another exemplary embodiment of a distaltip 112 c that includes a serpentine pattern 127. In this embodiment,the internal bends 128 of the serpentine pattern 127 may provide regionswhere other distal tips 112 c and/or obstructive material may becomeentangled, e.g., compared to providing a smooth edge 125, as shown inthe distal tip 112 a of FIG. 15A.

One advantage of the cage 144 shown in FIGS. 11A-13 is that the cage 144may facilitate deploying the cage 144 and/or advancing the cage 144 intoor through obstructive material within a body lumen. In contrast, thecage 44 shown in FIG. 1 is generally maintained substantially stationaryupon deployment within a body lumen, e.g., while the obstruction device40 is retracted to withdraw obstructive material into the cage 44. Forexample, the cage 144 of FIGS. 11A-13 may facilitate pulling material 52back into the open end 144 a of the cage 144 and/or separatingobstructive material from a wall of the body lumen 50.

During distal advancement, the cage 144 may be concurrently advanced androtated, e.g., manually or using a driveshaft connected to an electricmotor in a handle (not shown) of the apparatus 10 (see, e.g., FIG. 1).This may cause the distal tips 112 of the cage 144 to track along theinside wall of the body lumen 50, e.g., in a helical manner as the cage144 is advanced. When thrombus or other obstructive material isencountered, the distal tips 112 may pass between the material 52 andthe wall of the body lumen 50, thereby positioning the material 50inside the cage 144.

The distal tips 112 of the cage 144 may facilitate separation and/orcapture of material within the cage 144. For example, the edges of thedistal tips 112 may provide distal leading edges of the cage 144 thatare not a substantially smooth cylinder but define an undulatingsurface. Consequently, the distal tips 112 of the cage 144 may act as asaw by repeatedly making contact with the material 52 as the cage 144 isrotated, which may increase the chance of material 52 being dislodgedfrom the wall of the body lumen 50 and/or captured within the cage 144.To further ensure that the leading edge of the cage 144 passes betweenthe unwanted material and the wall of the body lumen 50, the distal tips112 and/or edges of the struts 116, 118 may also act as blades shearingalong the wall of the body lumen 50 to draw adherent material into thecage 144. Thus, the struts 116, 118 may cut or otherwise separate theinterface between the body lumen 50 and the obstructive material 52.

The distal tips 112 may be formed such that they conform substantiallyto the cylindrical shape of the cage 144, e.g., defining a diametersimilar to the rest of the expanded cage 144, although alternatively thedistal tips 112 may be biased radially outwardly, e.g., to ensure thatthe distal tips 112 pass between the wall of the body lumen 50 and theobstructive material 52 and/or enhance engagement of the distal tips 112against the wall of the body lumen 50. Alternatively, the distal tips112 may by biased to extend radially inwardly, e.g., laterally inwardly,relative to a central longitudinal axis of the apparatus 10, e.g., toprevent substantial risk of damage to the wall of the body lumen 50.

In addition, the different thicknesses and/or shapes of struts 116, 118may provide a cage 144 that responds in different ways depending uponwhich direction the cage 40 is rotated. For example, arrow “A” in FIG.13 represents a first direction for rotation of the cage 144. Ifresistance is encountered in the portions of the cage 144 contacting thewall of the body lumen 50 (not shown) during this rotation, torsion mayoccur. Because the thick struts 116 have a relatively high resistance tobending and the thin struts 118 are easily bent, the torsion may notbend the thick struts 116, but may cause the thin struts 118 to bend todefine a greater angle between the adjacent struts 116, 118 and expandthe cage 144 radially outwardly. This may increase the contact forcebetween the macerator cage 144, e.g., leading edges of the thick struts116, and the wall of the body lumen 50, which may increase the chancethat obstructive material being removed from the wall of the body lumen50 and being captured within the cage 144.

Optionally, the leading edges of the thick struts 116 may includesharpened edges or other features, which may enhance cutting or otherengagement with adherent material within the body lumen 50.

If the cage 144 is rotated in a second direction opposite to “A,” thetorsion may cause the thin struts 118 to bend due to their low columnstrength to reduce the angle between the adjacent struts 116, 118, andthe cage 144 may not expand radially outwardly in the same manner as thefirst direction.

This anisotropy with respect to rotational direction may be usefulbecause the cage 144 may be advanced and rotated in the “A” direction toengage and separate adherent obstructive material from a vessel wall,e.g., causing the material to enter into the cage 144. The torsion mayalso cause the cage 144 to expand outwardly for better apposition orengagement with the vessel wall. If the cage 144 encounters excessiveresistance, the cage 144 may be rotated in the second direction, e.g.,to disengage the resistance without causing radial expansion.

Depending on the stiffness differential between the thin and thickstruts 118, 116, rotation of the cage 144 in the second direction mayalso cause the cage 144 to radially contract to further facilitatedisengagement.

Turning to FIGS. 14A-14C, yet another embodiment of an expandable cage144 is shown, which may include an actuation mechanism for selectivelyopening and/or closing an open distal end 143 of the cage 144. Forexample, the distal end 143 of the cage 144 may be substantially closedby contracting the distal tips 112 radially inwardly, e.g., usingcontrol elements, e.g., one or more wires or filaments 114, coupled toeach of the distal tips 112. Alternatively, a single control element(not shown) may be threaded through each of the distal tips 112, e.g.,circumferentially and successively through holes in the distal tips (notshown), such that proximal tension on the control element may bend orotherwise direct the distal tips 122 radially inwardly. Optionally, alocking mechanism (not shown) may be provided for securing the distaltips 122 in the closed orientation, if desired. Alternatively, thedistal tips 122 may interlock with one another, e.g., as describedabove, to secure the distal tips 122 in the closed orientation.

FIG. 14A shows the distal end 143 open with the cage 144 in the expandedconfiguration, e.g., with the control elements 114 relaxed and thedistal tips 112 biased to a substantially axial, open configuration.FIG. 14B shows the distal tips 112 bent or otherwise directed inwardlytowards a closed configuration, e.g., after proximal tension is appliedto the control elements 114. The structure of the distal tips 112 mayfacilitate this bending by providing one or more preferential bendingfeatures, e.g., thinned strut widths, thinned strut thicknesses,perforated portions, and the like (not shown), to provide hinged regionsof the distal tips 112. In an alternative embodiment, shown in FIG. 14C,a tubular member 113 may be advanced over the control elements 114 tocause the distal tips 112 to bend radially inwardly.

The closed configurations shown in FIGS. 14B and 14C may allowobstructive material captured within the cage 114 to be substantiallyretained therein, e.g., without the need for an expandable obstructionmember 34, as described elsewhere herein. In these alternatives, thecage 144 may simply be withdrawn into a constraint tube or access sheath(not shown), thereby compressing the cage 144 radially inwardly.

With the distal tips 112 closed, the captured material may not simplyescape out the distal end 143 of the cage 144, but may remain within thecage 144 to be extruded through the apertures 146 (not shown in FIGS.14B and 14C) as the cage is compressed, e.g., to be aspirated, asdescribed above. Alternatively, the captured material may be withdrawninto the constraint tube or sheath along with the cage 144, also asdescribed above.

Turning to FIGS. 16A-16H, another exemplary method is shown for removingobstructive material from within a vessel or other body lumen 150, e.g.,using the cage 144 shown in FIGS. 11A-13. The cage 144 may be introducedinto the body lumen 150 via an access sheath and/or constraint tube 148,similar to the previous embodiments. As shown in FIG. 16A, the cage 144has been deployed and expanded within the body lumen 150 such that theopen distal end 143 is disposed adjacent to obstructive material 152intended to be removed. Once fully expanded, the cage 144 may be rotatedand advanced within the body lumen 150 toward the obstructive material152.

Turning to FIG. 16B, the distal end 143 of the cage 144 may engage thematerial 152, e.g., such that the distal tips 112 pass between thematerial 152 and the wall of the body lumen 152 to some degree, but arealso free to deform as they become entangled in the material 152.Optionally, an obstruction device (not shown) may be introduced throughthe material 152 and an obstruction member expanded beyond the material152 before the cage 144 is advanced. Thus, the obstruction member mayprevent distal migration of the material 152 away from the cage 144 asthe cage 144 is advanced.

With additional reference to FIG. 16C, upon further rotation of the cage144, the distal tips 112 may wind at least partially around the material152 and/or around each other, thereby creating a mechanical engagementbetween the cage 144 and the material 152. Further rotation of the cage144 may then be transmitted to the material 152, which may cause thematerial 152 to twist and/or otherwise detach from the wall of the bodylumen 150. After entanglement and further rotation, the entangledmaterial 152 may be completely removed from the wall of the body lumen150, as shown in FIG. 16D.

As shown in FIG. 16E, the cage 144 may then be withdrawn into the accesssheath and/or constraint tube 148, similar to the previous embodiments,thereby compressing the cage 144 radially inwardly towards the collapsedconfiguration. Because the distal tips 112 of the cage 144 aresubstantially straight and free on their distal ends (i.e. the cage 144is open ended and not attached to a core wire on its distal end), thedistal tips 112 may be disengaged and the material 152 released as thecage 144 is withdrawn into the access sheath 20. Thus, the separatedmaterial 152 may remain loose within the body lumen 150, as shown.

Thereafter, as shown in FIG. 16F, the cage 144 may be redeployed fromthe constraint tube 148 or sheath and expanded again with the open end143 disposed adjacent the loose material 152. The material 152 may thenbe pulled into the open end 143 of the cage 144, e.g., using anobstruction device 134, which may be the same device deployed beyond thematerial 152 previously or a different device introduced into the bodylumen 150 and beyond the material 152 before or after redeploying thecage 144.

Turning to FIG. 16G, the cage 144 with the material 152 captured thereinmay then be withdrawn into the sheath 20 or constraint tube (not shown),similar to the previous embodiments. As discussed elsewhere herein, anymaterial that protrudes through the apertures 146 in the cage 144 may besheared off or otherwise separated as the cage 144 is compressed, e.g.,to ensure that the cage 144 does not become lodged in the tip of thesheath 20. The cage 144 may be withdrawn completely into the sheath 20,as shown in FIG. 16H, and any remaining loose particles of the material152 may be aspirated through the sheath lumen, similar to the previousembodiments. For example, as described above, a vacuum may be applied bythe sheath 20 within the body lumen 150 at any time to aspirate looseparticles within the body lumen 150, e.g., released when the cage 144 isused to separate material from the wall of the body lumen 150 orthereafter. Any of these steps may be repeated as many times as desiredto remove any remaining material.

It will be appreciated that elements or components shown with anyembodiment herein are exemplary for the specific embodiment and may beused on or in combination with other embodiments disclosed herein.

While the invention is susceptible to various modifications, andalternative forms, specific examples thereof have been shown in thedrawings and are herein described in detail. It should be understood,however, that the invention is not to be limited to the particular formsor methods disclosed, but to the contrary, the invention is to cover allmodifications, equivalents and alternatives falling within the scope ofthe appended claims.

The invention claimed is:
 1. A method for removing obstructive materialfrom a body lumen, the method comprising: introducing a distal end of anelongate tubular member into the body lumen; introducing an elongatetreatment member comprising a distal balloon in a contracted conditionthrough a lumen of the elongate tubular member and into the body lumensuch that the balloon is positioned distal to the obstructive material;introducing a macerator device comprising an elongate shaft carrying anexpandable cage in a collapsed configuration through the lumen of theelongate tubular member into the body lumen such that the cage ispositioned proximal to the obstructive material; expanding the cagewithin the body lumen to an expanded configuration such that the cagedefines an open end; inflating the balloon; proximally withdrawing theinflated balloon towards the expanded cage such that the obstructivematerial is captured within the cage through the open end; collapsingthe cage radially inwardly towards the collapsed configuration to allowthe cage to be removed from the body lumen; and collapsing, after thecage capturing the obstructive material is collapsed, the balloon toallow the balloon to be removed from the body lumen.
 2. The method ofclaim 1, wherein the cage is introduced through the lumen of theelongate tubular member within a constraint tube that maintains the cagein the collapsed configuration, and wherein collapsing the cagecomprises withdrawing the cage back into the constraint tube.
 3. Themethod of claim 2, wherein a distal end of the constraint tube comprisesa sharpened edge for shearing off obstructive material extending throughapertures of the cage.
 4. The method of claim 3, further comprisingaspirating the obstructive material that is removed by the distal end ofthe constraint tube.
 5. The method of claim 1, further comprising:advancing the expanded cage towards the obstructive material androtating the cage during advancement until the obstructive materialbecomes entangled in a distal portion of the cage; continuing rotationof the cage until the obstructive material is detached from the bodylumen; redeploying and expanding, following collapsing the cage, thecage; and directing the obstructive material into the expanded cageusing the inflated balloon.
 6. The method of claim 1, wherein: inflatingthe balloon comprises delivering inflation media to an interior of theballoon; and collapsing the balloon comprises aspirating the inflationmedia from the interior of the balloon.
 7. The method of claim 1,further comprising aspirating the obstructive material.
 8. The method ofclaim 1, wherein the cage comprises a closed end opposite the open endthat is connected to the elongate shaft of the macerator device.
 9. Themethod of claim 1, wherein the cage comprises a closed end opposite theopen end that is connected to the distal end of the macerator device.10. A method for removing obstructive material from a body lumen, themethod comprising: introducing a distal end of a tubular member into thebody lumen, the tubular member comprising a lumen extending proximallyfrom the distal end; introducing a balloon in a contracted conditionfrom the tubular member into the body lumen to a location distal of theobstructive material within the body lumen; introducing a distal end ofa macerator device carrying an expandable cage in a collapsedconfiguration into the body lumen to a location proximal of theobstructive material from the tubular member; expanding the cage to anexpanded configuration within the body lumen such that an open end ofthe cage is oriented towards the obstructive material; inflating theballoon to an enlarged condition within the body lumen distal of theobstructive material; manipulating the balloon towards the cage, therebydirecting the obstructive material into the open end of the cage;retracting the cage after directing the obstructive material into theopen end of the cage; and collapsing, after the cage capturing theobstructive material is collapsed, the balloon to allow the balloon tobe removed from the body lumen.
 11. The method of claim 10, wherein thecage is introduced into the body lumen within a constraint tube thatmaintains the cage in the collapsed configuration and wherein expandingthe cage comprises deploying the cage from the constraint tube.
 12. Themethod of claim 11, wherein the cage slidably engages the constrainttube to direct the cage back towards the collapsed configuration. 13.The method of claim 12, wherein the cage comprises a tubular structureincluding a wall comprising a plurality of apertures, and wherein, whenthe cage slidably engages the constraint tube, the obstructive materialwithin the cage that extends through the apertures is separated from thecage by the constraint tube.
 14. The method of claim 13, furthercomprising aspirating the obstructive material separated from the cageinto the lumen of the tubular member.
 15. The method of claim 10,wherein: inflating the balloon comprises delivering inflation media toan interior of the balloon; and collapsing the balloon comprisesaspirating the inflation media from the interior of the balloon.
 16. Themethod of claim 13, wherein a distal end of the constraint tubecomprises a sharpened edge for shearing off the obstructive materialthat extends through the apertures of the cage.
 17. A method forremoving obstructive material from a body lumen, the method comprising:introducing a macerator device through a constraint tube into the bodylumen, the macerator device comprising an elongate shaft carrying anexpandable cage in a collapsed configuration; expanding the cage withinthe body lumen to an expanded configuration such that the cage definesan open end; advancing the expanded cage towards the obstructivematerial and rotating the cage during advancement until the obstructivematerial becomes entangled in a distal portion of the cage; continuingrotation of the cage until the obstructive material is detached from thebody lumen; withdrawing the cage into the constraint tube, therebyreleasing the obstructive material from the cage; redeploying andexpanding the cage; directing the released obstructive material into theexpanded cage through the open end using an embolectomy device; andcollapsing the cage radially inwardly towards the collapsedconfiguration to allow the cage to be removed from the body lumen. 18.The method of claim 17, wherein the open end of the cage comprises aplurality of separate substantially straight distal tips extendingdistally.